1. Technical Field
The disclosed embodiments relate to a light-emitting diode (LED) element, a manufacturing method of a light-guide structure thereof and an equipment of forming the light-guide structure thereof.
2. Description of the Related Art
Accompanied with gradual global resource depletion and ever-increasing environment-friendly awareness, green energy is now a highly valued subject. Among various types of green energy, the light-emitting diode (LED) and solar cell are considered as a mainstream in the green energy industry, and have matured with time. Compared to a conventional fluorescent lamp, the LED is free from mercury pollutions, and is at the same time advantaged by being light and small in size and power-saving as well as having a long lifespan. Moreover, ratios of materials forming the LED can be adjusted to change an emission color of the LED to diversified colors including red, blue, yellow and white to offer even more versatile applications. Therefore, apart from being utilized as a replacement for the fluorescent lamp, the LED may also serve as backlight sources of a monitor display to enhance performance and reduce a size of a display. In current white-light solid-state lighting, an indium gallium nitride (InGaN) LED playing a crucial role is particularly in demand. Therefore, it is an important topic as how to effectively increase light-emitting efficiency of the InGaN LED.
As the LED is targeted at being high in light intensity and high in efficiency, a first issue to overcome is element thermal effects that reduce external quantum efficiency (EQE) of an LED element. When an induced current increases, electric energy is reflected as thermal energy due to lowered optoelectronic conversion efficiency, such that the thermal energy is accumulated inside the element to reduce not only reliability but also lifespan of the element. Therefore, it is a focus of the industry to how to increase LED light-emitting efficiency to solve LED heat dissipation. Generally speaking, to increase LED light-emitting efficiency, a coarse surface is usually formed on a semiconductor layer through ablation when manufacturing the semiconductor layer.
However, a focusing process is needed to ablate a material so that energy is increased to a damage threshold to further achieve processing effects. The above process is yet quite time-consuming, and hence a laser manufacturing process is inapplicable to the optoelectronic semiconductor or manufacturing processes of other industries.